The present invention relates to a motor vehicle heating or air-conditioning system, with a water-removal device arranged in the fresh-air inlet duct, rising from the duct base and comprising a coarse-mesh lattice and a fine-mesh lattice resting against the latter, wherein the water removed by being carried away downwardly on the webs of the coarse-mesh lattice to the duct base which forms a water collection point with water drainage.
A known water-removal device extends over the entire duct cross-section and has a fine-mesh lattice placed in front of the coarse-mesh lattice, viewed in the flow direction as shown in German Patent No. 2,549,663.
It is an object of the present invention to provide a water-removal device with lattices lying in series and having a different mesh width such that the device has an air-guiding function in addition to the water-removal function.
This object has been achieved in a water-removal device in accordance with the present invention.
In a currently preferred embodiment of the present invention in which creates favorable flow conditions are created, the water-removal device is configured as a plate which extends transversely to the incident-flow direction and is inclined in the flow direction.
In another embodiment of the present invention, the water-removal device is formed as an air guide which projects approximately in a V-shape from the associated duct side wall and, on the incident air flow side, has only a coarse-mesh lattice, while the fine-mesh lattice is attached to the inside of the coarse-mesh lattice only from the vertex of the air guide. Droplet separation phenomena towards the free passage are thereby counteracted and the possibility of backflow to the rear side of the lattice against which the air flows is excluded.
To ensure that the air guide can be cleaned and, if required, exchanged, the air guide is covered at the top side by a portion of the upper duct wall which can be opened.
Unhindered water drainage is achieved if, together with the duct base and that portion of the upper duct wall which can be opened, the air guide surrounds a space from which the water drain leads off, because the air flow and the vacuum which arises due to it, which would prevent the water from flowing off, is deflected or weakened.
The dimensions of the coarse- and fine-mesh lattice which favorably influences the water-removal and air-guidance include a coarse-mesh width of 1 mm and a web width of 0.3 mm, and a fine-mesh width of about 0.25 mm and a web-width of about 0.1 mm.